1. Field of the Invention
The present invention relates to a battery suitable for an intermediate load.
2. Description of the Related Art
As a cylindrical battery, a wound battery for a heavy load such as a camera and a bobbin-type battery having a high capacity for a light load such as a backup have been commercialized. Among them, the bobbin-type battery has a simple configuration and can be produced at a low cost. However, the bobbin-type battery is poor in high rate characteristics due to a small electrode area. Herein, the heavy load refers to discharging, for example, at more than 300 mA, and the light load refers to discharging, for example, at less than 10 mA.
The wound battery for a heavy load is produced, for example, as follows. As a current collector, a foil or a net of a conductor such as metal and carbon, a woven fabric, a non-woven fabric, or the like is used, and the current collector is coated with an active mixture, followed by bonding under pressure. Thus, the current collector is integrated with the active mixture to form a long electrode. The electrode thus produced and a counter electrode are wound via a separator, whereby the wound battery is produced (see JP1(1989)-174854U). However, according to the winding system, a thin long electrode is wound, resulting in a complicated configuration, so that the wound battery is difficult to be produced and involves a high cost.
Furthermore, a lithium-thionyl chloride battery among non-aqueous primary batteries also has a bobbin-type configuration, and also is poor in high rate characteristics. As the recent application of a battery, there is an increasing demand for a current of about several 10 to 300 mA, for example, in information communication and the like. The above-mentioned battery is not suitable for such an intermediate load.